This invention is directed to a retracting agricultural irrigation sprinkler which can be withdrawn into the ground for tillage of the field and, on demand, its riser is thrust upward through the soil so that a motor in the top of the riser rotates the sprinkler nozzle mounted thereon for overhead irrigation sprinkling. When desired, the riser can be retracted for further tillage.
Many of the agricultural areas of the world have insufficient rainfall for directly satisfying the moisture needs of crops. Therefore, irrigation has been extensively used to aid in crop production in otherwise unsuitable areas. Historically, the water has been supplied by flooding channels adjacent the crop being irrigated. However, many crops can be more satisfactorily irrigated by overhead sprinkling. The advent of high-pressure pumps has produced water supplies which can be discharged through sprinkler heads to produce the overhead sprinkling. In addition to the simulation of rainfall conditions, the use of overhead sprinkling often conserves on the total water requirement.
All fields must be tilled for maximum crop production. As a consequence of this tillage requirement, portable sprinkler lines have been developed for placement on the surface after tillage is complete. These temporary sprinkler lines are satisfactory and the desired result is achieved, but require a considerable amount of manpower for the placement and removal of such lines. In order to save this manpower, devices for permanent underground burial have been developed. Carstenson U.S. Pat. No. 3,733,030 is an example of a device intended for such utilization. However, a number of problems in its configuration severely limit its widespread utilization.